What determines the price of sodium silicate in China?

What determines the price of sodium silicate in China?
Feedstock and modulus drive everything. Dry-process production dominates, using soda ash and quartz sand melted at 1,400-1,500 C, and soda ash jumped from RMB 1,250/t to 2,420/t in 2021 while sulfur rose 140%. Those moves squeezed downstream silica margins from 34.5% to 32.9%. Modulus matters too: higher silica-to-soda ratios (1.5-3.5 range) mean lower water solubility and harder dissolution, so high-modulus grades command different pricing than easy-dissolving low-modulus material. The old mirabilite route is effectively dead because of wastewater and emissions. With stricter environmental policy and rising labor costs, the RMB 1,670/t average is expected to keep climbing, though quality premiums separate export-grade from commodity material.